A kinetic study on non-isothermal crystallization of the glassy alloy Sb0.16As0.43Se0.41

A procedure has been used for analyzing the evolution with time of the volu me fraction crystallized and for calculating the kinetic parameters at non- isothermal reactions in materials involving formation and growth of nuclei. Considering the assumptions of extended volume and random nucleation, a ge neral expression of the fraction crystallized has been obtained as a functi on of the temperature for interior crystallization. The kinetic parameters have been deduced, assuming that the crystal growth rate has an Arrhenius-t ype temperature dependence, and the nucleation frequency is either constant or negligible. The theoretical method described has been applied to the cr ystallization kinetics of glassy alloy Sb(0.16)AS(0.43)Se(0.41) With and wi thout previous reheating. According to the study carried out, the values of the kinetic exponent, n, are 1.8 for the as-quenched glass and 0.9 for the reheated glass. As n decreases with reheating, it is possible to state tha t the annealing causes the appearance of new nuclei. The phases at which th e alloy crystallizes after the thermal process have been identified by X-ra y diffraction. Based on the diffractogram of the transformed material we su ggest the presence of microcrystallites of Sb2Se3 and AsSe, remaining in th e amorphous matrix. (C) 2000 Elsevier Science B.V. All rights reserved.